KR102527214B1 - Rollable display device - Google Patents

Abstract

A rollable display device capable of suppressing wrinkles of a flexible display panel is disclosed. The rollable display device includes a flexible display panel, a roller, an elastic holder, and a tension application unit. The roller is provided to wind the flexible display panel. The elastic holder is fixed to one edge of the flexible display panel and has a long side parallel to the edge. The tension applying unit is located at both ends of the elastic holder and tensions the elastic holder.

Description

Rollable display device {ROLLABLE DISPLAY DEVICE}

The present disclosure relates to a rollable display device capable of repeating a winding and unfolding operation of a flexible display panel.

A flexible display panel using a flexible plastic film instead of a hard glass substrate is being developed. The flexible display panel can be implemented in various types of display devices, such as a bendable display device, a rollable display device that can be rolled, and a foldable display device that can be folded in half. can

In a rollable display device, a flexible display panel is wound around a roller when not in use, and is released from the roller and unfolded when in use. Wrinkles may occur due to various causes while the flexible display panel is unfolded. Creases lead to image distortion, and if repeated rolling is performed after wrinkles occur, the flexible display panel may be damaged.

An object of the present disclosure is to provide a rollable display device capable of preventing image distortion and damage to the flexible display panel by suppressing wrinkles on the flexible display panel.

A rollable display device according to an exemplary embodiment includes a flexible display panel, a roller, an elastic holder, and a tension application unit. The roller is provided so that the flexible display panel can be wound. The elastic holder is fixed to one edge of the flexible display panel and has a long side parallel to the edge. The tension applying unit is located at both ends of the elastic holder and tensions the elastic holder.

A long side of the elastic holder may have a length equal to or greater than one edge of the flexible display panel, and the elastic holder may have a groove into which an edge of the flexible display panel is inserted. The rollable display device may further include a fixing frame surrounding the elastic holder. The fixing frame may include a cover surface and a side wall connected to an edge of the cover surface.

The tension applying unit may include a pair of nuts fixed to both ends of the elastic holder and a pair of bolts each fastened to the pair of nuts with a side wall of the fixing frame interposed therebetween. The rollable display device may further include a fixing unit fixing a portion of the elastic holder to the cover surface.

On the other hand, the rollable display device may further include a plurality of dampers disposed between the elastic holder and the cover surface of the fixing frame. The plurality of dampers may have greater elasticity than the elastic holder. When the flexible display panel is wound around the roller, the plurality of dampers may be provided to stretch the flexible display panel along the pulling direction.

The tension applying unit may be provided to slide along the direction in which the flexible display panel is pulled with respect to the fixed frame. The tension applying unit may include a pair of nuts fixed to both ends of the elastic holder and a pair of bolts each fastened to the pair of nuts with a side wall of the fixing frame interposed therebetween. A pair of long holes for sliding each pair of bolts may be formed on the side wall.

The rollable display device may further include an optical sensor and a roller moving unit. An optical sensor may be installed in a housing surrounding the roller, and may detect wrinkles and skewed rolling of the flexible display panel by taking pictures of the flexible display panel. The roller moving unit may be coupled to the roller to move the roller in the axial direction.

When the flexible display panel is skewed in one direction while being wound around the roller, the roller moving unit may correct the skew of the flexible display panel by moving the roller in one direction.

The roller moving unit may include a roller support coupled to a lower portion of the roller to support the roller, and a moving motor coupled to the roller support through a power transmission unit to move the roller support. The power transmission unit may include a rotating screw fixed to the moving motor and a nut block fixed to the roller support and screwed to the rotating screw.

The rollable display device can flatten the flexible display panel to improve display quality and prevent wrinkles when the flexible display panel is wound. In addition, reliability of the product may be improved by suppressing damage to the flexible display panel due to wrinkles.

1 is a perspective view of a rollable display device according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of the rollable display device shown in FIG. 1 .
FIG. 3 is a partially exploded perspective view of the rollable display device shown in FIG. 1 .
4A and 4B are partial cross-sectional views of the rollable display device cut along line IV-IV of FIG. 1 .
5 is a front view of a rollable display device according to a second exemplary embodiment of the present invention.
6 is a partially exploded perspective view of a rollable display device according to a third exemplary embodiment of the present invention.
7A and 7B are partial cross-sectional views of a rollable display device according to a third exemplary embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. This invention may be embodied in many different forms and is not limited to the embodiments set forth herein.

Throughout the specification, when a part such as a layer, film, region, or plate is said to be “on” another part, this includes not only the case where it is “directly on” the other part, but also the case where another part is present in the middle. And "~ on" means to be located above or below the target part, and does not necessarily mean to be located on the upper side relative to the direction of gravity.

In the entire specification, when a part "includes" a certain component, it means that it may further include other components unless otherwise stated. Since the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of description, the present invention is not limited to the drawings.

A rollable display device according to an exemplary embodiment will be described with reference to FIGS. 1 to 4B .

1 is a perspective view of a rollable display device according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view of the rollable display device shown in FIG. 1 . FIG. 3 is a partially exploded perspective view of the rollable display device shown in FIG. 1 , and FIGS. 4A and 4B are partial cross-sectional views of the rollable display device taken along line IV-IV of FIG. 1 .

First, referring to FIGS. 1 and 2 , the rollable display device 100 of the first embodiment includes a flexible display panel 10 (hereinafter referred to as a 'display panel' for convenience) for displaying an image, and a display panel It includes a roller 20 provided so that the roller 10 can be wound, a housing 30 accommodating the roller 20 therein, and a fixing frame 40 coupled to one edge of the display panel 10 .

The display panel 10 is a display panel in which a plurality of thin film transistors and a plurality of pixels are formed on a flexible plastic film, and has a property of being easily bent like paper.

The display panel 10 may be an organic light emitting display panel that does not require a backlight. An organic light emitting display panel may include a flexible substrate, a plurality of thin film transistors and a plurality of organic light emitting diodes formed on the flexible substrate, and an encapsulation layer covering and sealing the plurality of organic light emitting diodes.

In this embodiment, the display panel 10 may have a substantially rectangular planar shape having two pairs of linear edges facing each other. One edge of the display panel 10 is coupled to the fixing frame 40 , and the opposite edge of the display panel 10 is fixed to the roller 20 . For convenience, one edge coupled to the fixed frame 40 is referred to as a first edge 11, and the opposite edge fixed to the roller 20 is referred to as a second edge 12.

The display panel 10 includes a display unit 13 on which a plurality of pixels are formed to display actual images, and a non-display unit 14 (or a dummy unit) surrounding the display unit 13 . The first edge 11 and the second edge 12 of the display panel 10 are spaced apart from the display unit 13 by a predetermined distance.

At least some edges of the non-display portion 14 may be formed as a relatively narrow area compared to the display portion 13 to the extent that it is difficult to distinguish them with the naked eye, or may be omitted. That is, at the left and right edges that are not fixed to the fixed frame 40 or the roller 20, the non-display portion 14 may be formed as an extremely narrow area or may be omitted.

The roller 20 is located inside the housing 30 and is rotated in a forward or reverse direction by a motor 21 . In the standby mode, the display panel 10 is wound around the roller 20 and stored inside the housing 30 . In the use mode, the display panel 10 is released from the roller 20 and unfolded. When the display panel 10 is wound around the roller 20 and when it is unwound, rotational directions of the roller 20 are opposite to each other.

A separate mechanical component (not shown) may be provided to automatically unfold the display panel 10 wound around the roller 20 and maintain the unfolded state by supporting the unfolded display panel 10 . For example, a mechanical configuration of lifting the fixed frame 40 upward and maintaining a constant distance between the housing 30 and the fixed frame 40 when the fixed frame 40 is maximally raised is the housing 30 and the fixed frame 40. It may be installed between the fixed frames 40.

Referring to FIGS. 3 to 4B , the first edge 11 of the display panel 10 is not directly coupled to the fixing frame 40 , but via the elastic holder 51 and the tension applying unit 55 . coupled to (40). The elastic holder 51 and the tension applying unit 55 serve to suppress wrinkles of the display panel 10 . This will be described in more detail.

The first edge 11 of the display panel 10 is fixed to the elastic holder 51 . The elastic holder 51 is an approximately rod-shaped member having a long side parallel to the first edge 11, and may be formed to have the same length as the first edge 11 or to a length greater than the first edge 11. .

In FIGS. 3 to 4B , the case where the elastic holder 51 is formed to have a length longer than the first edge 11 of the display panel 10 is illustrated as an example. The elastic holder 51 may be made of an elastic material such as synthetic rubber.

A groove portion 52 may be formed on one side of the elastic holder 51 facing the display panel 10 , and the non-display portion 14 adjacent to the first edge 11 may be fitted into the groove portion 52 . The non-display portion 14 inserted into the groove portion 52 may be fixed to the elastic holder 51 by a fixing means such as an adhesive. The adhesive may be applied to both the front and back surfaces of the non-display portion 14 .

The tension applying unit 55 is located at both ends of the elastic holder 51 in the longitudinal direction and tensions the elastic holder 51 . For example, the tension applying unit 55 is attached to the nut 56 with a pair of nuts 56 fixed to both ends of the elastic holder 51 and the sidewall 42 of the fixing frame 40 interposed therebetween. It may be composed of a pair of bolts 57 fastened to each other. The longitudinal direction of each bolt 57 is parallel to the first edge 11 .

Since the position of the bolt 57 is fixed by the side wall 42 of the fixing frame 40, the nut 56 moves when the bolt 57 rotates. Accordingly, the position of the nut 56 can be determined according to the rotation direction and amount of rotation of the bolt 57, and the degree of tension of the elastic holder 51 can be controlled by adjusting the distance between the pair of nuts 56. That is, as the distance between the pair of nuts 56 increases, the elastic holder 51 can be tensioned more strongly.

FIG. 4A shows a state before the elastic holder 51 is stretched, and FIG. 4B shows a state after the elastic holder 51 is stretched due to the movement of the nut 56 . In FIG. 4A, the nut 56 maintains a distance between the sidewall 42 of the fixed frame 40 and D1, but in FIG. 4B, the nut 56 is in contact with the sidewall 42 of the fixed frame 40.

The fixed frame 40 may include a cover surface 41 and four side walls 42 connected to edges of the cover surface 41 . The four side walls 42 surround the elastic holder 51 and the nut 56 so that they are not exposed to the outside. Circular openings 43 may be formed in two of the four side walls 42 through which the bolts 57 pass.

The elastic holder 51 receives a force extending in the longitudinal direction by the tension applying unit 55 . Assuming that the entire elastic holder 51 is fixed to the cover surface 41 of the fixing frame 40, the elastic holder 51 is not tensioned smoothly. Therefore, the entire elastic holder 51 may be spaced apart from the cover surface 41 of the fixing frame 40 .

However, in this case, when the display panel 10 is wound around the roller 20, since the force is concentrated on the tension applying part 55, a part of the elastic holder 51 is part of the fixing part 53 within a range that does not affect the tension. It can be fixed to the cover surface 41 of the fixing frame 40 by. The fixing part 53 may fix the central part of the elastic holder 51 to the cover surface 41 of the fixing frame 40 . The position of the fixing part 53 is not limited to the central part of the elastic holder 51 .

Meanwhile, the tension applying unit 55 is not limited to the aforementioned bolt-nut assembly. The tension applying unit 55 can be applied to any mechanical configuration capable of tensioning the elastic holder 51 and maintaining the tension state.

In the rollable display device 100 of the first embodiment, the first edge 11 of the display panel 10 is tensioned using the elastic holder 51 and the tension applying unit 55, and the display panel 10 is flat. raise the level Therefore, wrinkles of the display panel 10 around the first edge 11 can be suppressed, and image distortion or damage to the display panel 10 caused by wrinkles can be prevented in advance.

Next, a rollable display device according to a second embodiment will be described with reference to FIG. 5 .

5 is a front view of a rollable display device according to a second exemplary embodiment of the present invention.

Referring to FIG. 5 , the rollable display device 200 according to the second embodiment includes an optical sensor 60 that detects wrinkles of the display panel 10 and a roller 20 in an axial direction (left or right side based on the drawing). ) and a roller moving unit 70 for moving.

The optical sensor 60 is installed on the top of the housing 30 and observes the wrinkles of the display panel 10 by photographing the front or rear side of the display panel 10 . The optical sensor 60 may be configured as a normal camera. The detection signal of the optical sensor 60 is transmitted to the control unit 65, and the control unit 65 can automatically control the roller moving unit 70.

The roller moving unit 70 includes a roller support 71 supporting the roller 20, a moving motor 72 generating power for moving the roller support 71, a roller support 71 and a moving motor 72 ) and a power transmission unit 73 connecting the The roller support 71 is coupled to the roller 20 by a bearing (not shown) to enable rotation of the roller 20, and supports the roller 20 at a lower portion of the roller 20.

The power transmission unit 73 may include a rotating screw 74 fixed to the moving motor 72 and a nut block 75 fixed to the roller support 71 and screwed to the rotating screw 74 . One end of the rotary screw 74 is fixed to the moving motor 72, and the other end is coupled to the bearing 76. The nut block 75 may be provided as a pair, and the pair of nut blocks 75 may be screwed to the rotation screw 74 at a distance from each other.

When the moving motor 72 rotates in the forward direction, the rotary screw 74 also rotates in the forward direction, and the nut block 75 and the roller support 71 move in one direction while moving the entire roller 20 in one direction. Conversely, when the moving motor 72 rotates in the reverse direction, the rotation screw 74 also rotates in the reverse direction, and the nut block 75 and the roller support 71 move in the other direction while moving the entire roller 20 in the other direction.

The direction and amount of movement of the roller 20 can be precisely controlled according to the direction and amount of rotation of the moving motor 72 . On the other hand, the power transmission unit 73 is not limited to the above configuration, and is composed of a Linear Motor rail (LM rail) and an LM block (Linear Motor guide, LM guide) It can be implemented in several different mechanical forms, such as

When the use mode is converted to the standby mode, the display panel 10 is wrapped around the rotating roller 20 and stored inside the housing 30 . When a misalignment occurs between the roller 20 and the display panel 10 while the display panel 10 is wound around the roller 20, the display panel 10 is wound outward from the roller 20 and wrinkles are formed. can happen

Referring to FIG. 5 , when the optical sensor 60 detects a phenomenon in which the display panel 10 is tilted toward the left side and wound, the controller 65 rotates the moving motor 72 in a forward or reverse direction, and the roller support 71 is moved leftward to move the entire roller 20 leftward.

Conversely, when the optical sensor 60 detects a phenomenon in which the display panel 10 is wound while leaning toward the right side, the controller 65 rotates the moving motor 72 in a reverse or forward direction and moves the roller support 71. Moving in the right direction moves the entire roller 20 in the right direction.

As such, the controller 65 corrects the bias of the display panel 10 by moving the roller 20 in the direction in which the display panel 10 is biased, and suppresses wrinkles caused by the bias. Accordingly, the display panel 10 can be accurately wound at a designated position of the roller 20 , for example, at the center of the roller 20 without causing wrinkles.

The roller moving unit 70 mainly operates when the display panel 10 is wound to correct the bias of the display panel 10, and operates minutely even when the display panel 10 is unfolded to change the position of the display panel 10. can be used to fine-tune the

The rollable display device 200 of the second embodiment has the same configuration as the first embodiment except for adding an optical sensor 60, a control unit 65, and a roller moving unit 70. All features of the rollable display device according to the first embodiment described above with reference to FIGS. 1 to 4B are applicable to the rollable display device according to the second embodiment.

Next, a rollable display device according to a third embodiment will be described with reference to FIGS. 6 to 7B .

6 is a partially exploded perspective view of a rollable display device according to a third embodiment of the present invention, and FIGS. 7A and 7B are partial cross-sectional views of the rollable display device according to the third embodiment of the present invention.

Referring to FIGS. 6 to 7B , the rollable display device 300 of the third embodiment includes a plurality of dampers 80 installed between the fixing frame 40 and the elastic holder 51 .

The plurality of dampers 80 may be formed of a material having greater elasticity than the elastic holder 51, and are installed side by side at a distance from each other between the cover surface 41 of the fixed frame 40 and the elastic holder 51 . The plurality of dampers 80 may be made of synthetic rubber or springs.

When the display panel 10 is wound around the roller 20 due to rotation of the roller 20 , the display panel 10 receives a downward pulling force. When the display panel 10 receives a downward pulling force, the plurality of dampers 80 distribute the force concentrated on the display panel 10 while being stretched along the direction in which the display panel 10 is pulled, (10) balances the tension received.

FIG. 7A shows a state before the plurality of dampers 80 are tensioned, and FIG. 7B shows a state after the plurality of dampers 80 are tensioned.

At this time, in order for the plurality of dampers 80 to be tensioned, the elastic holder 51 and the tension applying unit 55 must be coupled to the fixing frame 40 in a sliding state. To this end, as shown in FIG. 6 , the opening 431 provided in the sidewall 42 of the fixing frame 40 through which the bolt 57 passes is formed as a long hole in the direction in which the display panel 10 is pulled. can

In this case, when the display panel 10 receives a pulling force, the elastic holder 51 moves downward while the bolt 57 slides down along the opening 431, and the plurality of dampers 80 stretched in the up-down direction.

The rollable display device 300 according to the third embodiment is similar to the first or second embodiment except that the plurality of dampers 80 are added and the opening 431 of the fixing frame 40 is formed as a long hole. It consists of the same composition as All features of the rollable display device according to the first embodiment described with reference to FIGS. 1 to 4B and the rollable display device according to the second embodiment described with reference to FIG. 5 are all features of the rollable display device according to the third embodiment. Applicable to all devices.

The rollable display devices 100, 200, and 300 of the first to third embodiments described above can flatten the display panel 10 to improve display quality and prevent wrinkles when the display panel 10 is wound. . In addition, reliability of the product may be improved by suppressing damage to the display panel 10 due to wrinkles.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited thereto, and it is possible to make various modifications and practice within the scope of the claims and the detailed description of the invention and the accompanying drawings, and this is also the present invention. It is natural to fall within the scope of

100, 200, 300: rollable display device
10: flexible display panel 20: roller
21: motor 30: housing
40: fixed frame 42: side wall
51: elastic holder 55: tension application unit
56: nut 57: bolt
60: optical sensor 70: roller moving unit
71: roller support 72: moving motor
73: power transmission unit 74: rotating screw
75: nut block 80: damper

Claims (14)

flexible display panels,
a roller provided to wind the flexible display panel;
an elastic holder fixed to one edge of the flexible display panel and having a long side parallel to the one edge;
A tension applying unit located at both ends of the elastic holder and tensioning the elastic holder in a long direction of the elastic holder, and
Includes a fixed frame surrounding the elastic holder,
The rollable display device of claim 1 , wherein the fixing frame includes a cover surface and a sidewall connected to an edge of the cover surface. According to claim 1,
a long side of the elastic holder has a length equal to or greater than one edge of the flexible display panel;
The rollable display device of claim 1 , wherein the elastic holder has a groove into which an edge of the flexible display panel is fitted. delete According to claim 1,
The tension applying unit,
A pair of nuts fixed to both ends of the elastic holder, and
A pair of bolts respectively fastened to the pair of nuts with the sidewall of the fixing frame interposed therebetween
Rollable display device comprising a. According to claim 1,
The rollable display device further includes a fixing part fixing a part of the elastic holder to the cover surface. According to claim 1,
The rollable display device further comprises a plurality of dampers positioned between the elastic holder and a cover surface of the fixing frame. According to claim 6,
The plurality of dampers have greater elasticity than the elastic holder. According to claim 6,
The rollable display device of claim 1 , wherein the plurality of dampers extend along a direction in which the flexible display panel is pulled when the flexible display panel is wound around the roller. According to claim 8,
The rollable display device of claim 1 , wherein the tension applying unit slides with respect to the fixed frame in a direction in which the flexible display panel is pulled. According to claim 9,
The tension applying unit,
A pair of nuts fixed to both ends of the elastic holder, and
And a pair of bolts respectively fastened to the pair of nuts with the sidewall of the fixing frame interposed therebetween,
The rollable display device of claim 1 , wherein a pair of long holes for sliding each of the pair of bolts are formed on the sidewall. According to claim 4,
an optical sensor installed in a housing surrounding the roller and detecting wrinkles and biased rolling of the flexible display panel by photographing the flexible display panel; and
Roller moving unit coupled to the roller and moving the roller in the axial direction
A rollable display device further comprising a. According to claim 11,
When the flexible display panel is biased in one direction while being wound around the roller, the roller moving unit corrects the bias of the flexible display panel by moving the roller in the one direction. According to claim 11,
The roller moving part,
A roller support coupled to a lower portion of the roller to support the roller, and
A moving motor coupled to the roller support through a power transmission unit to move the roller support
Rollable display device comprising a. According to claim 13,
The power transmission unit,
A rotating screw fixed to the moving motor, and
A nut block fixed to the roller support and screwed to the rotating screw
A rollable display device comprising a.

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